BLOOD-VESSELS OF THE HEART VALVES 451 



there are muscle fibres in the valves. These are supposed to be 

 confined to the basal third of the valve, and it is probably the 

 rule that in the adult these structures are limited to this region. 

 Numerous studies of the musculature of the valve have been 

 made. In Tandler's (7) recent ''Anatomie des Herzens," the 

 situation is summed up as follows: 



Corresponding to their developmental process, the atrio-ventricu- 

 lar valves of the embryo contain considerable muscle and a corre- 

 sponding number of blood-vessels. This musculature has a close rela- 

 tionship to the auricular musculature, so that in fetal hearts and those 

 of young children, vessels are seen extending as far as this musculature. 

 In the fetal heart, and in the young heart, vessels extend from the 

 papillary muscles to the chordae tendineae and along through to the 

 valve. The vessels diminish along with the muscle fibres of the 

 chordae and valves. The almost muscle-free semilunar valves are 

 also practically devoid of vessels. When islands of muscle tissue 

 remain in the thin portions of the valves, delicate blood vessels can be 

 shown to be present here. 



In 1903, Koniger (8) published an elaborate monograph on 

 endocarditis. His studies of the normal anatomy are mostly 

 literary, as he admits on page 23, he has not attempted to in- 

 ject normal heart-valves. He grants the vascularity of fetal 

 valves and acknowledges that hematomata and hemangiomata 

 are found at times in the normal valves of new born and young 

 children. He attributes these conditions to vascular rests in the 

 valves, and accepts Langer's position on the absence of blood 

 vessels in adult valves. 



The more recent studies of Nussbaum (9) are more convincing. 

 He succeeded in finding blood-vessels in the atrio-ventricular 

 valves of new born, child and adult. Figure II on page 465 is a 

 sketch of the vascular network in the membranous portion of a 

 mitral valve. He was not able, however, to inject vessels in the 

 semilunar valves or chordae tendineae. 



The experimental endocarditis produced by Rosenow (10) by 

 intravenous injection of bacteria give a more pathological cor- 

 roboration to the findings of the anatomists who have demon- 

 strated heart-valve vessels. After injection of streptococci, 

 pneumococci and staphylococcus albus, in rabbits, Rosenow 



